Plants with a Purpose
Architectural plants give your garden structure, shape and impact, just one or two in a normal sized garden can be enough to bring character and individuality to an otherwise average garden.
So what makes a plant an architectural plant? It is usually large and has to stand out from other plants so look to such things as large leaves, large flowers or flower spikes, dramatic colouring and the like.
Perhaps two of the easiest to grow from seed are bronze fennel and cardoon (cynara cardunculus). Both will grow to more than 2 metres tall whilst having a diameter of around 750 mm, and both have culinary uses. The fennel has a fine frondy foliage with a bronzy tint which tastes of aniseed and can be used in salads or as a herb, usually in fish dishes. Cardoons are like globe artichokes to look at large jagged leaves and with a large thistle-like flower; it is, however, the stem of the cardoon, not the flower which is eaten. The stems must be tied up in black plastic for 6 weeks before harvesting, and then boiled for at least ½ an hour to tenderise them after this they can be sautéed and are very tasty.
A bit shorter than these two at about 1.5 m is acanthus mollis (or spinosus), bears breeches, which has large jagged leaves and dramatic spikes of purple and white flowers.
Large leaved plants would include fatsia japonica, a shrub to about 2m, which can give a garden a very tropical feel, and the very similar but smaller fatshedera lizei. Rodgersias have a range of shades of leaf and flower reasonably well. The extreme leaf is gunnera maculata which has massive leaves on 21/2 m tall prickly stems and is only suitable for very large damp areas but is absolutely stunning in the right place
Architectural trees would include the monkey puzzle, many cedars, especially cedar of Lebanon. Catalpas the Indian bean tree, have long, impressive seed pods. There are a couple of hardy palms which will help to create a tropical feel the well-known chusan palm, and the smaller trachycarpus wagnerianus
Climbers might include clematis armandii which has fragrant white flowers in Spring and trachelospermum jasminoides., again having fragrant flowers.
A fern, dryopteris crassirhizoma will grow up to a metre tall
Invasive types, only suitable for large areas include paulownia tomentosa, the foglove tree, which is cut down each spring and will grow to 2m high with leaves 750mm across before the end of summer! Jungly or what!! Bamboos make very architectural hedges, but some are very invasive choose your variety carefully!